Potassium ion channels are an integral part of a functional cell. Channels play a role in the regulation of the cell membrance potential, and when coupled to receptors, function in signal tansduction patheys. It is the signal transduction pathway that enables cell to cell coummunication, and ultimately, enables the fine-tuning and regulation of entire organ systems. Specifically, the opioid are receptoeds are coupled to potassium ion channels. Upon binding of a agonist to the receptor, the receptor, the receptor recruits the channel and influences the permissivity of the channel to potassium ion flux, casuing an inwardly rectifying current and cell deoplarization. This process is important in many bodily functions, including reuronal activity, gastric mobility, analgesia, and addiction. Both the opiod receptor and the G-protein coupled to be used in this proposal have been cloned, however the method in which these proteins interact upon binding of ligand is unknown. Recent development of atomic force miscroscopy (AFM) has enabled the possibilty of studing the structure of membrane proteins in living cells. The potential of AFM for bioloical systems in the study of physical structure in conjunction with currently available methods in eletrophysiology for functionl analysis. This noval approach will provide a solid foundation for the further research in cell and regulation via potassium channels.